platform/x86: oxpec: Make turbo val apply a bitmask

platform/x86: oxpec: Make turbo val apply a bitmask

On the OneXPlayer G1, the turbo register is multiplexed and contains an
extra bit (0x02) which is set on boot. Therefore, we should only change
the 0x40 bit to not affect other behavior. Collapse the disable and
enable functions, and apply a mask for the turbo bit instead.

Tested-by: Joshua Tam <csinaction@pm.me>
Suggested-by: Joshua Tam <csinaction@pm.me>
Signed-off-by: Joshua Tam <csinaction@pm.me>
Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
Link: https://lore.kernel.org/r/20250426172955.13957-2-lkml@antheas.dev
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>